Evaluation of antimicrobial and antibiofilm efficacy of different antimicrobial peptides on multispecies biofilm of endodontic pathogens

Background: Assessing and evaluating the function and activity of different types of antimicrobial peptides (AMPs) in suppressing multispecies endodontic pathogens is necessary. Aim: The study was conducted to assess the antimicrobial and antibiofilm efficiency of gramicidin S, D-cateslytin (D-Ctl), GH-12, and DJK-5 AMPs on multispecies biofilm formed by endodontic pathogens. Methodology: Multispecies biofilm comprising Enterococcus faecalis, Actinomyces naeslundii, Lactobacillus salivarius, and Streptococcus mutans were formed on 80 hydroxyapatite disk samples. Sixteen samples were allocated for each peptide in the experimental group (n = 16) and eight samples each for the control group, 2% sodium hypochlorite (positive control) and normal saline (negative control). The total number of colony forming units (CFUs) and biofilm intensity to fluorochrome in each study group were measured using the culture method and dual stain fluorescence microscopy method. The differences across groups were compared using Tukey’s multiple comparisons test and one-way analysis of variance (α =0.05). Results: DJK-5 (CFU = 110/ml), gramicidin (CFU = 110/ml), and D-Ctl (CFU = 60/ml) peptides showed statistically significant correlation with respect to CFUs and similar antibiofilm activity (P < 0.01), whereas GH-12 (CFU = 90/ml) peptide revealed differences that were not statistically significant (P > 0.05). Conclusion: DJK-5, gramicidin S, and D-Ctl peptides demonstrated remarkable efficacy against multispecies oral biofilms of S. mutans, L. salivarius, A. naeslundii, and E. faecalis. Saline showed least antimicrobial and antibiofilm activity. Sodium hypochlorite (NaOCl) showed strongest difference when compared to peptides or saline, validating it as a potent control. Hence, these peptides can be employed as potential antibiofilm agents in endodontic treatment procedures for better outcomes.